Removing leading, trailing and multiple spaces within a string

Removing leading, trailing and multiple spaces within a string

I would like to remove all leading and trailing spaces. As well as replace
multiple spaces with a single space within a string, so that all words in
a string are separated exactly by single space.
I could achieve this using following two iteration of regex and looking
for single regex solution.
s/^\s+|\s+$//g
s/\s+/ /g
Sample Input:
word1 word2 word3 word4
Desired Output:
word1 word2 word3 word4
It would be appreciable if you could help me to solve this.